The invention is particularly well suited for use in a side entry pivot pin arrangement of a rotary F coupler, where it is important to prevent excessive compression of the draft gear against the butt end of the shank of the coupler front follower during the mounting of the coupler in the rotary mechanism within the yoke, since such compression makes it extremely difficult for an operator to properly position and pin the shank to the rotary mechanism. Moreover, such compression also causes undue wear of the butt end of the shank during dumping of a car and rotation of the draft gear relative to the coupler, which wear can radically decrease the productive life of the coupler.
Some yokes in use today have a set of stops for restricting movement of the front follower in the direction of the shank of the coupler, but these yokes require special front followers and are simply not capable of accommodating conventional front followers used in non-rotary type couplers. The invention is directed to solving this problem by the provision of an improved design which permits interchangeably using different front followers.
Briefly stated, the invention is in a car coupler and draft gear arrangement. Means are provided for maintaining the front follower of the draft gear in unbiased relation against the adjacent butt end of the coupler shank, or a desired clearance or contact between the butt end of the coupler shank and adjacent front follower. Such means includes a set of lugs disposed on the yoke and designed to engage a plurality of stops that are carried by the front follower. The stops project from a planar portion of the front follower and together with the lugs are arranged and sized to provide the desired clearance between the front follower and adjacent butt end of the shank when the coupler is in a neutral position intermediate the normal buff and pull positions.
Another aspect of the invention is the provision on the front follower of a highly improved buffing surface, the lateral curvature of which substantially equals the correspondingly measured lateral curvature of the butt end of the coupler shank.
Thus, the invention has the advantage of providing more buffing contact between the coupler and draft gear and the alternate use of conventional front followers normally used with non-rotary type couplers.